Construction of ENV-116G Turbine 1

 Construction of ENV-116G Turbine

1. Turbine Casing

• The turbine casing consist of a casing rear, and a casing front bolted together at the vertical joint
• When removing the casing front it must be lifted horizontally enough to clear the rotor blades in order to prevent the possibility of damage to the blades.

2. Turbine Blades

• Blades is so important part for turbine at point of high efficiency and reliability that designing and construction are paid very careful attention, that especially sectional shape of blade is manufacturedd with skillful engineering of long experiment and development at our shop.
• The turbine blading consist of one row of stationary blade, and two row of rotating blades which are made of 12% Cr. Stainless Steel, the surface is finished elaborately.
• The rotating blades are mounted on rotor with T-root, and their tops are cramped each other with several shrouds.
• The stationary blades are mounted on retainer with dovetail.

3. Turbine Rotor

• The rotor disc is shrunk and keyed on the pinion shaft which overhung from two pinion bearings.
• The disc is careful heat treated Ni-Cr Steel. After the blades are installed, the entire rotating assembly is dynamically.

4. Nozzle and Stationary Blade Retainer

• The nozzle made of 13% Cr. Stainless Steel rings, is distributed to all circumference of the roror in order to get large power. And its all surface, especially steam path is finished elaborately with reamer drill.
• The nozzle ring is bolted up the steam chest firmly.
• The stationary blade retainer is fitted to casing by sliding. And its all surface, especially steam path is finished elaborately with reamer drill.
• The nozzle ring is bolted up the steam chest firmly.

5. Turbine Gland

• The turbine casing opening around the shaft are sealed by means of carbon ring glands.
• The gland seals the shaft opening againts leakage of steam to atmosphere in non-condensing unit, or leakage of air into the turbine in condensing units.
• Three carbon rings are holded between gland diapragm, and one ring is made up of three segments held together aroundthe shaft by a garter spring.
• The segment are made of carbon material consolidated with a suitable bind and accurately machined to size.
• The quality of these rings is held to a special specification by the exercise of most rigid inspection.
• The garter springs are made of 18 - 8 Cr-Ni stainless steel wire and this wire is insured longer life forthese springs than could otherwise be expected.
• The pinion shaft which is in contact with the carbon rings is protected hard chrome plating, and it keeps resist from wear and corrosion.
• Non condensing service, the leakage steam through two carbon rings is led to leakage steam condenser or atmosphere.
• Therefore, the last carbon ring seals steam leakage to atmosphere. Condensing service sealing steam which is injected to the gland between firts carbon ring and second carbon ring, prevent the air leakage into the turbine casing.
• The leakage steam is led to the leakage steam condenser or atmosphere.
• The leakage steam piping be paid the attention that the steam have no pressure.
• The suitable sealing steam source pressure is 0.2kg/cm2 G - 0.4 kg/cm2 G.
• If gland leakage has been observed the rings should be refutted by carefully grinding the ends of the reduce the clearance.
• This should be carefully done taking not more than about 0.025 mm at a time off each face. ( 0.025 off each end of each segment will reduce the ring diameter roughly 0.05 mm)
• If spare gland rings are in stock they will be dimensioned to have the standard clearances show in the illustration.
• If these spare are installed in a unit operating at relatively high temperature, it is advisable to start up the unit very cautiously the firts time, making sure that the glands function properly and show no signs of being tight. 
• The gland ring is formed beveled section.